Provided herein are various devices and methods that measure real-time perineal pressures during bicycle riding. The devices and methods are particularly useful for design of bicycle seats for comfort and to minimize risk of erectile dysfunction (ED) for a rider. Furthermore, the devices and methods can be used as a tool to assess ED risk for a rider using a specific bicycle seat, wherein the rider uses the seat under real ride conditions.
An important component of bicycles is the bicycle seat. Much work has gone into developing bicycles seats that are comfortable and perform well under different conditions ranging from the recreational to the competitive user. There has been increasing recognition that bicycle riding can be a significant risk factor for ED (see, e.g., Ben E. Benjamin “Cycling and Your Health” Massage Therapy Journal. 2004). In particular, due to the positioning of the rider and seat geometry, it is not uncommon for riders to experience discomfort in the perineal region, particularly for longer-duration rides. In fact, genital numbness due to cycling is observed and riders report impaired sexual function and increase in ED. Accordingly, numerous studies have further investigated the relationship between bicycle riding and ED.
For example, Huang et al. (“Bicycle Riding and Erectile Dysfunction: An Increase in Interest (and Concern)” J. Sex. Med. 2005:596-604) summarizes various scientific publications in peer-reviewed journals from 1981 to 2004 and concludes that “bicycle riding more than 3 hours per week was an independent relative risk . . . for moderate to severe ED.” The authors of that study hypothesize that “straddling bicycle saddles with a nose extension is associated with suprasystolic perineal compression pressures, temporarily occluding penile perfusion and potentially inducing endothelial injury and vasculogenic ED.”
Such a conclusion is based, at least in part, on studies using stationary bikes with sensors on the saddle that suggest bicycling may cause ED. For example, Schrader et al. (2002) used a “thin profile resistance-based pressure measurement mat . . . placed over the saddle” to measure pressure exerted between the rider and the bicycle saddle. “Nocturnal Penile Tumescence and Rigidity Testing in Bicycling Patrol Offices” J. of Andrology (2002) 23(6): 927-934. Pressure distribution maps were illustrated for a man sitting on a chair and in different positions on a bicycle saddle (normal/upright or in pursuit position). The results of that study suggested “prolonged bicycle riding may have negative effects on nocturnal erectile function and indicate a need for innovative bicycle saddle designs.” A similar follow-on study of bicycle police officers assessed the effectiveness of “no-nose bicycle saddle as an ergonomic intervention” for sexual dysfunction. Schrader et al. “Cutting Off the Nose to Save the Penis.” J. Sex. Med. (2008): 5:1932-1940 (see also Lowe et al. “Effect of Bicycle Saddle Designs on the Pressure to the Perineum of the Bicyclist.” Med. Sci. Sports Exerc. (2004) 36(6): 1055-62).
Substantial effort has been directed to the impact of seat geometry on various factors related to ED. Munarriz et al. calculated a crude mean pressure exerted by subjects on their perineum when straddling a saddle (weight/surface area) and concluded that seat geometry can have a significant impact on penile hemodynamics. “Only the Nose Knows . . . ” J. Sex. Med. (2005) 2:612-619. Breda et al. measured partial pressure of penile transcutaneous oxygen “to investigate the differences of compression from two different saddles on the vascular structures of the perineum.” “Development of a New Geometric Bicycle Saddle for the Maintenance of Genital-Perineal Vascular Perfusion.” J. Sex. Med. (2005) 2:605-611. That study suggests specific seat geometry was effective in “limiting the compression on the pelvic floor.” A National Institute for Occupational Safety and Health report (“No-nose Saddles for Preventing Genital Numbness and Sexual Dysfunction from Occupational Bicycling” NIOSH Pub. No. 2009-131) reports no-nose saddles are effective “in reducing pressure in the groin and improving the sexual health of male bicycle patrol police officers” and that no-nose saddles may also benefit women.
There is, however, a fundamental flaw in those studies with respect to an accurate measure of pressure exerted on the perineum. Each of those studies estimate or measure the pressure exerted by the bicycle rider on the bicycle seat. Although a force exerted by a user on a surface is matched by a corresponding force exerted by the surface on the user, relying on a measure of the force on the bicycle seat does not provide information about the force exerted by the seat on a specific region of the user, including the perineum region. In particular, studies that position the pressure sensor on the bicycle seat do not provide an accurate indication of the pressure exerted on the perineal region, and specifically on a perineal blood vessel. This is especially problematic as a bicycle rider is constantly moving with respect to the saddle so that a pressure on the seat cannot be reliably correlated with a specific region of the perineum. Instead, the pressure sensor on the bicycle seat measures pressure exerted by the rider onto the bicycle seat and, depending on how the rider is seated, non-perineal regions may exert significant pressure on the seat surface. Accordingly, there is a need in the art for systems that can reliably and accurately measure a force or a pressure on the perineum of a user positioned on a bicycle seat in order to precisely evaluate risk of ED by various bicycle seat geometries.